A team of researchers using Satellite Thermography has identified a massive, unrecorded industrial city of the Nok Culture in Central Nigeria. The thermal imaging detected over 200 distinct heat signatures from ancient iron-smelting furnaces arranged in a planned urban grid, suggesting a level of industrial organization previously unknown in early African civilizations.
The city, which dates to roughly 400 BCE, features centralized processing hubs and large-scale slag heaps that indicate a massive output of high-quality iron. This discovery challenges the theory that ironworking in sub-Saharan Africa was a purely decentralized, village-based activity.